feat(realtime): keep projects and labels current too, not only tasks

The socket carried task events and nothing else, so a project or a label
created anywhere — another tab, another device, Claude through the
connector — did not appear until a reload. Tasks updated live and the
sidebar did not, which reads as the sidebar being broken rather than as a
gap in what is published.

Projects and labels go to the *user* rather than to a project. A project
that has just been created has no subscribers, because nobody was
watching a thing that did not exist a moment ago.

Labels are announced as "something changed" and re-read, rather than sent
as a payload. The sidebar wants each label's task count, which no single
event carries and which moves whenever a task gains or loses a label —
including through quick add, where "@regnskab" invents the label inside a
task write and no label event is sent at all. Comparing the label lists
on a task change is what catches that, without re-reading on every ticked
checkbox.

And projects now go through an upsert, because the same row arrives twice
— once as the response to the request that created it, once over the
socket. Appending both puts two ids into a keyed {#each}, which throws
and stops the sidebar rendering. The tasks already had that guard; adding
the project event without it reintroduced the identical bug, and the
smoke test caught it on the first run.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

web/src/lib/components/Sidebar.svelte

@@ -27,7 +27,11 @@
 	let filters = $state([]);
 	let labels = $state([]);
 
+	// Reads app.labelsChanged so the effect re-runs when a label is created,
+	// renamed or deleted anywhere — including in another tab, or by Claude
+	// through the connector.
 	$effect(() => {
+		app.labelsChanged;
 		api.listFilters().then((r) => (filters = r.filters)).catch(() => {});
 		api.listLabels().then((r) => (labels = r.labels)).catch(() => {});
 	});